When you order food using your iPad or tablet, your subconscious brain is tricked into buying more than you intended.

Isn’t it great that you can do so many things with iPad apps? Well, maybe it isn’t always so great. Psychologists and food industry experts now agree that when we use an iPad or tablet to order food we end up buying more than we would if we ordered over the phone.

The implications aren’t difficult to work out. First, you become fatter and unhealthier because you’re eating more. Secondly, you end up handing over more of your hard-earned money to your favorite food outlets.

So if you don’t want to gain weight or lose money by ordering food on your iPad, try thinking about these six ways you’re likely to overindulge .

1) You’re A Kid In A Candy Store

When you order by phone, many times you just order from memory. But online is a different matter. You can see the whole menu in one go. And if you see more options, you might want to order more.

Like a kid in a candy store, you want everything. Amir Eisenstein, marketing officer for online ordering service Eat24’s explains:

“The difference between online ordering and offline is that most restaurants tell us orders are bigger and higher. For example, if you order a pizza over the phone you’ll just tell them to bring an XL pizza and a Coke. But when you go online, you see the whole menu. All of a sudden, people order appetizers, ribs, salads, and stuff they don’t normally order over the phone.”

3) You Love To Customize

Many of us are happy with ordering the standard items on the menu. But when you have an iPad in front of you, it’s no effort at all to add a little twist to your order. A slice of cheese here, a splash of mayo there.

These extras may seem like fun at the time, but they quickly add up, in calories and cash. Joel Sheetz, founder of a large chain of convenience stores explains how touch-screens offer limitless choices for customizing your order:

“We can offer condiment screens, vegetable screens, and a whole bunch of choices people can take their time going through. You find that some people have interesting tastes, thanks to the touchscreen (laughs). They will put mayo on something you and I would never put mayo on. Some of things you add on to a sandwich are free, others are upcharges, which are right on the button—like bacon, cheese.”

4) You Order More Impulsively

We all know it’s a bad idea to do the weekly shop when you’re hungry. Ordering food online has the same risks. Online retailers know all about the psychology of impulse buying. It’s their job to use clever tactics to persuade us to buy more. And when you’re hungry your brain is likely not at it’s peak performance.

5) You’re In Love With Your iPad

Face it: ordering on your iPad is fun. Sometimes you might order just for the fun of it, or for the sake of novelty. Young people are particularly susceptible to this kind of foodie techno-lust. In a recent survey, two of three 18- to 34-year-olds said they’d like to see more technology in restaurants, such as iPads instead of menus.

6) New Food Apps Are Becoming More Like Games

As retail increasingly moves into the online space, restaurants are also starting to offer fancy ordering tools. Last year Domino’s launched a pizza ordering app incorporating a 3D custom pizza builder. This trend for creating game-like experiences increases customer engagement and associates food ordering with fun, taking your mind away from the cost and the calories.

What to Expect Next

The next big step will be about gathering data about fo customers in the same way Amazon does. This will allow the food outlets to create more personalized experiences for customers. Whilst this will undoubtably bring some improvements to food ordering, the danger, as we’ve seen above is that the increasingly sophisticated marketing techniques will lead consumers towards unhealthy and costly food choices.

So next time you’re hungry at home and about to order a pizza, consider these six psychological reasons and how if you order with your iPad you might be putting inches on your waistline, and at the same time making a dent in your bank account.